Pests are a biological factor that damages crops regardless of the region where they are. Damage caused by pests in the crops reduces the quality of the product and the amount of production, since they prevent plants to have an optimal development, and depending on the pest and the level of infestation, they can cause the death of the host.
Among the pests that affect the crops significantly, both in quality and in quantity, are the phytoparasitic nematodes, which are microscopic and depending on their life cycle they affect the plant in different ways. Some of the damages they cause to the crops are: withering, chlorosis, dwarfism, rickets, defoliation, lack of vigor, necrosis of the affected parts, resulting in a weak crop or the death thereof, and therefore production loss. In an effort to control pests that attack crops, farmers are in need to use chemical pesticides. Some of the disadvantages of them are the high risk posed when applied; the presence of the same in food products can result in damage to the health of consumers; also the alteration of pH and the contents of minerals in phytotoxic amounts as a consequence of the excessive application of chemical pesticides results in the loss of fertility of the soil; additionally they can have an effect in the quality of the product, as well as generating resistance to the chemical agents, which results in the need of make use of a larger amount thereof.
In the state of the art diverse methods for nematode control are described; among them are chemical methods, such as: use of 2R,5R-dihidroxymethil-2R,4R-dihidroxypyrrolidine (Pat. No. WO/1999/059414); a chemical agent with condensed formula C27H30O9 (Pat. No. WO/1993/002083); use of fluopiram for nematode control (Pat. No. WO/2012/038476); fertilizer composition based on 1-70% potassium hypophosphite and ammonium phosphite, 1-307 boric fertilizer (Pat. No. CN101492323), among others.
On the other hand, there are biological methods where microorganisms are used for nematode control, these include: Sphingobacterium strain spiritivorum C-926 and Corynobacterium paurometabolum C-924 (Pat No. MX 250042); Pasteuria spp. (Pat No. MX 193344); fungi of the genus Arthrobotrys (Pat No. U.S. Pat. No. 4,666,714); Bacillus thuringiensis (Pat No. U.S. Pat. No. 5,270,448); Streptomyces dicklowii ATCC 55274 (Pat No. U.S. Pat. No. 5,549,889); fungus Pochonia chlamydosporia var. chlamydosporia (Pat No. US2009169518); Verticillium chlamydosporium CC 334168 (Pat No. WO/1991/001642), among others.
Another option is the combination of chemical compounds with biological agents, such as: Buprofezina and Paecilomyces sp. (U.S. Pat. No. 5,885,598); Silafluofen and/or Etofenprox with Paecilomyces sp. (U.S. Pat. No. 5,888,989), among others. Finally, there are methods that involve genetic modification for generating crops resistent to nematodes, such as those described in the following patent documents: GEP20002245, U.S. Pat. No. 6,294,712, U.S. Pat. No. 7,576,261, CN1903014, WO/2003/080838, among others.
The disadvantages that have been observed with chemical methods are those described above for the application of nematicides; as regarding the combination of chemical agents with biological agents, although sometimes is achieved to decrease the amount of the chemical agent, the disadvantages do not disappear; the genetic alteration of crops in order to create pest-resistant crops is an option that, besides having a high cost, poses a long-term risk for the consumers, since there is no certainty about the implications that the consumption of such products will have in the long term.
Nowadays, the biological methods are the most accepted and convenient, because they use microorganisms that are safe for the final consumer and help preserve the quality of soils, crops and thus of the final product.
Currently, the fungus of genus Paecilomyces spp. is used as nematicide, since it attacks nematodes effectively and without damaging crops. Patent documents U.S. Pat. No. 7,435,411 B2, CN101418264 and US 20050008619 describe the use of a composition containing Paecilomyces lilacinus for pest control in the soil; patent documents U.S. Pat. No. 5,989,543, CN101422168, DE102005024783, CN101081982, CA2059642, U.S. Pat. No. 5,360,607, U.S. Pat. No. 5,989,543, CN101518265 describe the use of Paecilomyces lilacinus; Paecilomyces fumosoroseus, Paecilomyces lilacinus 251, Paecilomyces lilacinus 252, Paecilomyces lilacinus 253, and Paecilomyces lilacinus 254; and Paecilomyces cicadae for nematode control and finally, in patent application MX/a/2011/004510 the use of Paecilomyces carneus strain IE-431 is described for the prevention and/or control and/or eradication of cyst-forming nematodes in solanaceous crops.
Among the highest-risk nematodes for crops are the gall-inducer nematodes of genus Meloidogyne spp., among others; root-lesion and root-borers, which are migratory endoparasites, including nematodes of genera Ditylenchus spp., Pratylenchus spp. and Radopholus spp., among others; and migratory and sedentary endoparasites, including nematodes of genera Helicotylenchus spp., Criconemoides spp., and Xiphinema spp., among others. The main crops affected by said nematodes are shown in Table 1:
TABLE 1Crops affected by nematodesCommonnameScientific nameMeloidogynePratylenchusHelicotylenchusCriconemoidesSwiss chardBeta vulgarisXAgaveAgave atrovirensXXXXAvocadoPersea americanaXXXXGarlicAllium sativumXAlfalfaMedicago sativaXXXCottonGossypiumXXXhirsutumSugar-appleAnona spp.XXRubber treeHevea brasiliensisXRiceOryza sativaXXOatAvena sativaXBambooBambusa spp.XBegoniaBegonia spp.XEggplantSolanumXmelongenaPeanutArachis hypogeaXXXCoffeeCoffea arábicaXXCocoaTheobroma cacaoXXZucchiniCucurbita pepoXShe-oakCasuarina spp.XCamelliaCamelia spp.XSweet potatoIpomea batatasXCinammonCinnamomum zeylanicumXSugar caneSacharum officinarumXXXSafflowerCarthamus tinctoriusXXWhite onionAllium cepaXXCedarChamaecyparis spp.XCitrus plantsCitrus spp.XXXCoconut treeCocos nuciferaXCauliflowerBrassica oleracea var. BotrytisXXXCarnationDianthus caryophyllusXXXChrysanthemumChrysantemum morifoliumXChayoteSechium eduleXChiliCapsicum annumXXPeachPrunus persicaXXEpazoteChenopodium ambrisioidesXSpinachSpinacea oleraceaXLoofahLufa cylindricaXStrawberryFragaria spp.XXXWhite ashFraxinus americanaXBeanPhaseolus vulgarisXXXGardeniaGardenia jasminoidesXChickpeaCicer arietiumXGladiolusGladiolus spp.GuavaPsidium guajava spp.XBroad beanVicia fabaXFigFicus caricaXMexican YamPachirizus angulatusXLettuceLactuca sativaXXXLemmonCitrus lim{acute over (o)}nXMaizeZea maysXXXApple treeMalus spp.XXXMangoManguifera indicaXXXDaisyAster spp.XShasta DaisyChrysantemum m{acute over (a)}ximumXXMelonCucumis meloXXXXMintMentha piperitaXXXYamDioscorea spp.XWalnut treeJuglans regiaXXXPrickly pearOpuntia spp.XXOkraAbelmoschus esculentusXPapayaCarica papayaXPotatoSolanum tuberosumXXXBarnyard grassEchinocloa spp.XXCucumberCucumis sativusXBananaMusa spp.XXXJamaica pepperPimenta dioicaXPinePinus sppXMexican mountain pinePinus hartwegiiXPineappleAnanas comunusXXXXPummeloCitrus maximaWatermelonCitrullus lanatusXXWhite willowSalix albaXSorghumSorghum vulgareXSoyGlycine maxXXTobaccoNicotiana tabacumXXTomatoLycopersicon esculentumXXXGround cherryPhysalis spp.XXCommon wheatTriticum aestivumXTrigoBuckwheatXVineVitis viniferaXXXMadagascar periwinkleVinca roseaXAfrican violetSaint paulina spp.XCarrotDaucus carotaXCommonnameScientific nameRadopholusHoplolaimusXiphinemaDitylenchusSwiss chardBeta vulgarisAgaveAgave atrovirensXXAvocadoPersea americanaXXXGarlicAllium sativumXXAlfalfaMedicago sativaXXXCottonGossypiumXXhirsutumSugar-appleAnona spp.XRubber treeHevea brasiliensisRiceOryza sativaXXOatAvena sativaBambooBambusa spp.BegoniaBegonia spp.EggplantSolanummelongenaPeanutArachis hypogeaXCoffeeCoffea arábicaCocoaTheobroma cacaoXXXZucchiniCucurbita pepoShe-oakCasuarina spp.XCamelliaCamelia spp.Sweet potatoIpomea batatasCinammonCinnamomum zeylanicumXSugar caneSacharum officinarumXSafflowerCarthamus tinctoriusWhite onionAllium cepaXCedarChamaecyparis spp.Citrus plantsCitrus spp.XXXXCoconut treeCocos nuciferaCauliflowerBrassica oleracea var. BotrytisXXCarnationDianthus caryophyllusXChrysanthemumChrysantemum morifoliumChayoteSechium eduleXChiliCapsicum annumXXPeachPrunus persicaXXXEpazoteChenopodium ambrisioidesSpinachSpinacea oleraceaLoofahLufa cylindricaStrawberryFragaria spp.XXXWhite ashFraxinus americanaBeanPhaseolus vulgarisXXGardeniaGardenia jasminoidesXChickpeaCicer arietiumXGladiolusGladiolus spp.XGuavaPsidium guajava spp.Broad beanVicia fabaFigFicus caricaMexican YamPachirizus angulatusLettuceLactuca sativaLemmonCitrus limonMaizeZea maysXXXApple treeMalus spp.XXMangoManguifera indicaXDaisyAster spp.Shasta DaisyChrysantemum maximumMelonCucumis meloXMintMentha piperitaXYamDioscorea spp.Walnut treeJuglans regiaXXPrickly pearOpuntia spp.OkraAbelmoschus esculentusPapayaCarica papayaXXPotatoSolanum tuberosumXXXBarnyard grassEchinocloa spp.XXXXCucumberCucumis sativusXBananaMusa spp.XXXJamaica pepperPimenta dioicaPinePinus sppXMexican mountain pinePinus hartwegiiPineappleAnanas comunusXPummeloCitrus maximaXWatermelonCitrullus lanatusXWhite willowSalix albaSorghumSorghum vulgareXXSoyGlycine maxXTobaccoNicotiana tabacumXXTomatoLycopersicon esculentumXGround cherryPhysalis spp.Common wheatTriticum aestivumXTrigoBuckwheatVineVitis viniferaXMadagascar periwinkleVinca roseaAfrican violetSaint paulina spp.CarrotDaucus carota
Sedentary endoparasitic nematodes are those that deform the roots of different crops due to inducing the overgrowth of the cells in the feeding site within which causes root galls (Meloidogyne spp.).
Migratory endoparasitic nematodes completely penetrate in the root of its host, traveling through the cortex and feeding on the cytoplasm of the cells, thus causing extensive destruction of tissues, and causing atrophy in the radicular system of plants (Ditylenchus spp., Pratylenchus spp., and Radopholus spp., among others).
Semiendoparasitic nematodes are deeply affixed to the host plant, leaving part of the body exposed to the outside. The juvenile are released to soil when hatching out, and subsequently they affix to the root of the plant (Heterodera spp., and Punctodera spp., among others).
Sedentary ectoparasitic nematodes only introduce the cephalic part of their body in the host plant, and usually do not become detached, except for reproduction. They oviposit directly in the soil (Helicotylenchus spp., Tylenchorhinchus spp., and Criconemoides spp., among others).
Migratory ectoparasites feed on a specific place during a short time and only introduce the stylet in the root of the plant. Some induce the formation of syncytia; a multi-nucleated hyperplastic cell where the nematode feeds (Xiphinema spp., Longidorus spp., and Trichodorus spp., among others).
Agriculture is the most important productive sector on most of the countries, where has a significant place in employment generation, the overall increase in agricultural incomes is a necessary condition for stimulating the growth of the entire economy, including non-agricultural sectors that sell their products and services to the rural population.
Mexico has a national territory of 198 million hectares, of which 145 million are dedicated to livestock, this is why agriculture represents an important productive sector, with a contribution of 4% to the national gross domestic product, is a core activity in rural areas, in which a highly significant part of the national population still inhabits.
The climatic differences between different regions of the world and even between regions in each country are significant in terms of climate and ecosystem, so pest control in crops in those regions is vital for farmers to be competitive nationally and internationally.
Therefore, it is necessary to have a method for pest control that works in different conditions of the soil and ambient, which also do not affect the quality of the product or the health of producers and/or consumers; in the present invention is disclosed the use of a fungus for nematode control, with outstanding efficacy and efficiency and inexpensive.